As for piezoelectric/electrostrictive ceramics for an actuator, lead zirconate titanate (PZT) is used in many cases. A ratio of titanium (Ti)/zirconium (Zr) in PZT is adjusted in the vicinity of the morphotropic phase boundary (MPB) in many cases. A third component such as lead niobate zincate (Pb(Zn1/3Nb2/3)O3) is introduced into PZT in some cases. In addition, Ti and Zr are replaced with a donor element having a higher valence such as niobium (Nb) in some cases. Thus, electric field responsiveness of a domain is improved, and electric-field-induced strain becomes large.
In piezoelectric/electrostrictive ceramics in Patent Document 1, lead antimonate zincate (Pb(Zn1/3Sb2/3)O3) is introduced to PZT. In piezoelectric/electrostrictive ceramics in Patent Document 2, Pb(Zn1/3Sb2/3)O3 is introduced to PZT and further modification is performed.